Put the quad on a list and turn it on in 2wd and only rears should move, the fronts may move but a simple touch should stop them. Switch to AWD, all should spin, and nothing should stop them. If in 2wd your fronts are moving enough that a touch will not stop the rotation, your hubs need more or less hub oil (is this a 2004.5 or 2004?) Didn't they switch mid year from the out-board hubs with fluid, to in-board ones within the diff? Sound like fluid or cage problems.

Steve